Steam-engine indicator



(No Model.) 2 Sheets-Sheet 1.

W. S. M0 KAY.

STEAM ENGINE INDICATOR. v

Patented May 27, 1,890k

1,1 l lll ma noms ruins co., mum uw (No Model.) 2 sheetsE-sheet 2.

W. S. MoKAY. I

* STEAM ENGINE INDICATOR.

No. 428,933. Patented May 27, 1890.

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HHH K Img/ I( @WA/55555. /NVEN TDH' I f ,24j @am W lUNITED STATE-:sPATENT OFFICE.

WALTER S. ll/ICKAY, OF EAST BOSTON, MASSACHUSETTS.

STEAM-ENGINE INDICATOR.

SPECIFICATION forming part of Letters Patent No. 428,933, dated May 2*?,1890. Application filed June l0, 1889. Serial No. 313,773. (No model.)

To aZZ whom it may concern:

Be it known that I, WALTER S. MCKAY, of East Boston, in the county ofSuffolk and State of Massachusetts, have invented certain new and usefulImprovements in Steam-Engine Indicators, of which the following is aspecification.

This invention relates to steam-engine indicators, the action of which,when suitably attached to the cylinder of a steam-engine, will determinethe pressure of the steam in said cylinder at all points of the strokeof the piston.

The invention has for its obj ect to provide an indicator of the classmentioned, which may be adapted for use on either a right or left handengine or on either cylinder of a double engine, so that one instrumentonly will be required, instead of two, as heretofore.

The invention also has for its object to provide a simple and effectiveparallel motion whereby the pencil attached to the instrument may bemoved in a straight line, and thereby be made to trace an accuratediagram.

The invention also has for its object to provide improved means forreadily adjusting the different parts in their operative position whennecessary to changethe instrument from right to left, or vice versa.

The invention consists in the improvements which I will now proceed todescribe and claim.

Of the accompanying drawings, forming a part of this specification,Figure l represents a side elevation of an indicator provided with myimprovements. Fig. 2 represents a sectional view of the cylinder of thesame and a side elevation of the pencil-operating devices, hereinafter`explained. Figs. 3, 4, e, and 5 represent detail views, hereinafterreferred to. Fig. G represents a longitudinal section through thepaper-cylinder shown in Fig. l. Fig. 7 represents a section on line 7 7,Fig. 6, looking downwardly. Fig. 8 represents a top plan view of theinvention as shown in Fig. l.

The same letters of reference indicate the same parts in all of thefigures.

In the drawings, referring to Figs. l and 2, A represents thesteam-cylinder, B the papercylinder, indcatoran instrument and D thepiston, of a Thompson well known to those skilled in the use of suchdevices and forming no part of my invention, but to which myimprovements in the present instance are preferably attached.

In the applicationy and use of the indicator, connection being made witheach end of the engine-cylinder by suitable appliances, steam from saidcylinder is admitted to the indicator-cylinder, which forces the pistonupwardly in the cylinder of the indicator against the tension of aspiral spring suitably secured to the piston and resting against thehead of the cylinder. To the piston-rod is attached a sleeve providedwith a socket at its lower end adapted to receive the lower end of abar. The latter being connected at its upper end to the pencil-carryingarm, said arm is connected at its outer end to a radius-bar and isadapted to move between vertical parallel guides secured to an arm,

the arrangement being such that the pencil is moved in a vertical lineby the piston andk intermediate connections above described. Thepaper-cylinder is revolved to correspond to the movement of the pistonby suitable devices which it is not necessary here to describe.

The foregoing is simply a description of the operation of indicators ingeneral use, and in carrying out my invention I have made certain newand useful improvements which I will now proceed to describe and claim.

Referring to Figs. l and 2, a a represent parallel vertical guidessuitably secured to an arm b, formed integrally with or spitablyattached to a sleeve c, surrounding the upper portion of the cylinder Aand iitted thereto, so that it may be revolved thereon. CZ represents anarm, which is commonly called the pencil-carmen7 on 4the outer end ofwhich is formed a sleeve c, adapted to fit the space between the guidesa d', so that it may move freely therebetween. In said ysleeve isinserted a pencil f, (see Fig. 8,) adapted to trace a diagram in acommon and well-known manner. g represents what I term the socket-bar,said bar being connected to the pencil-arm at its upper end, andextending TOO downwardly into a sleeve 7L, having a socket thepiston-rodi by a screw-threaded connection with the same. A step or stud7c is inserted in the enlarged portion oi' the pistonrod, and thesocket-bar is adapted to lightly bear against the same, so as to take upall vertical play and allow the arm to be rocked easily, the arrangementbeing' such that a ball-and-socket joint is formed, whereby the bar mayaccommodate itself to the radiusimparted thereto through the pencil-armwhen the latter is moved between the guides, as shown in dotted lines inFig. 2 and on an enlarged scale in Fig. 5.

It will be understood by the foregoing that I am enabled to provide asimple, durable, and accurate parallel motion, which is an import-antfeature oi' my invention.

The paper-cylinder l5 is provided with a coiled drum-spring Z, thetension of which may be regulated for different speeds of engines. Saidspring is adapted to operate the carrier disk or drum m, to which thecylinder is detaehably secured. (See Fig. 0.) Said carrier-disk isprovided with a groove, Figs. l and G, for the reception of a cord n,adapted to be attached to the cross-head of the engine through suitabledevices.

Heretofore considerable difficulty has been experienced in guiding thecord to the grooved carrier-disk on, as the connection with the engineis frequently made at sharp angles and the range of adjustment has beenlimited. To this end I have provided a leading-pulley o, which consistsof a grooved pulley ai'iixed to a bracket p, having a polygonal shankadapted to lit a socketed standard q', secured to an adjustablebase-plate fr, held in position by a thumb-nut .s to the spindle t, onwhich the carrier-disk rotates. Said bracket-shank q is provided with ascrew-threaded portion a, Fig. 4, to which a milled disk-nut /U isattached, by which the pulley may be held in position. The cord passesover the pulley, which is always in line with the carrier-disk, as shownin Figs. l, 8, and 3, and passes through the portion q, as shown in Fig.l, (which is asectional view on line at l of Fig. 1,) and around thecarrier-disk n1.

It will be seen by reference to Figs. l and Jr that the wheel o may beset at any angle permitted by the number ot' sides of the polygonalportion and insures a superior means for guiding the cord than has beenused heretofore. Fig. 3 shows the leading-wheel set at one of theangles, which will serve to make clear the point just described.

As before stated, the carrier-disk is provided with a drum-spring I,adapted to move said carrier, and with it the paper-cyli nder, in thedirection opposite to that in which it is rotated bythe cord. In usingthe instrument with engines of varying piston-speed the tension of thespring must necessarily be regulated-that is, in case of a high-speedengine the spring' must have increased tension, and vice versa. In orderto secure a convenient means of adjustment, I have provided a collar n',placed upon the spindlet amnd adapted to be turned thereon. Said collar1s provided en its upper side near its outer edge with a series of holes2 2 2, with which a set-screw is adapted to engage, thelatter beingattached to a ixed arm li on the spindle. 'lhe collar is provided on itsunder side with a hub b', having means for attaching one end of thespring' Z thereto, the other end of the spring being attached to thecarrierdrum. The spindle t being held in a fixed position bythe wing-nuts, it will be seen that the arm being xed to the spindle, forms aneffective means of adjustment, as by simplyloosening the screw 5, so asto allow the collar 1u to be turned on the spindle, more or less tensionmay be given to the spring as occasion may require, as most clearlyshown in Figs. t3 and 7.

I have shown in Fig. 7 a device for stopping the paper-cylinder whennecessary without unhooking or disconnecting the connect'.- ing-cord,which device consists of a lever c, pivotedon the supportingarm d', andhaving a strip of leather or other suitable material c secured to oneside thereof, adapted to engage the peripheryof the lower portion of thecarrier-disk m. An arm f', formed on the lever and extending out asufficient distance therefrom to exert sufficient leverage for theapplication of the brake, secures a convenient means for stopping thecylinder, as will be readily understood by reference to theabovementioned ligure.

In changing the instrument from a lefthand (as shown) to a right-hand Iproceed as follows: By reference to Fig. S it will be seen that thepencil-carrying bar d is provided with an offset, and that the guides aa are in line with the center of socket-barg and radius-bar g', so thatwhen the pins or studs which connect said socket-bar and radius-bar tothe pencil-carrying lever and the latter reversed and the arm I) swungaround on its sleeve to the position shown in dotted lines in saidligure, the leading-wheel and its support being adjusted to thedotted-line position shown in said ligure, and at the same time the armis slipped up on the shaft by removing tapering pin 8, allowing collar wto be raised sufficiently to reverse spring Z and the change is madewhich obviates the necessity of two instruments instead of one.

IIaving thus explained thc nature of my improvements and described oneof the Vforms oi' their construction,`as also a mode of their use, Ideclare that what I claim isn l. In a steam-engineindicator, thecombination of the indicator-cylinder and its piston, the sleeverevoluble on said cylinder, the pencilcarrier having a socket at itsouter end, the radius bar or link pivoted at one end to saidpencilcarrier and at its other end to said sleeve, the bar or rod g,pivotally connected at its upper end to said pencil-carrier and at itsother end to the piston, the paper-cylinder, the arm l), rigid with saidsleeve, and the ver- ICO IIO

tical parallelrguides a a', connected to said arm, substantially as setforth, the pencil being guided by said latter arms, as stated.

2. In a steam-engine indicator, the combination of the carrier-disk, avertical standard having a lateral polygonal socket, alaterallyextendingbracket having a polygonal shank corresponding with said socket in whichthe shank is adapted to be held and adj usted, and the leading-pulleyjournalcd upon said bracket, all as set forth.

3. In a steam-en gine indicator, the combination, with the carrier-disk,of the leading-pnlley, a bracket to which said pulley is journaled, saidbracket being provided with a polygon ally-formed shank and ascrew-threaded portion, a supporting-standard provided with a polygonalsocket conforming to the polygonal portion of the bracket shank, and amilled nut adapted to be screwed upon the screw-threaded portion of saidshank, as set forth.

4. In a steam-engine indicator, the combination, with the spindle, thecarrieredrum and drum-spring, one end of which is attached to thecarrier-drum, of a collar adapted to rotate on said spindle and providedon its upper face With a series of holes and yhaving a hub to which theother end of the spring is i attached, an arm fixed to the spindle, anda set-screw in said arm adapted to engage the holes in the face of saidcollar, as set forth.

5. In a steam-engine indicator, the combination, with thc paper-cylinderand carrierdru1n,of the brake for stopping the revolution of the drumWithout disconnecting the cord, consisting of the pivoted lever c',having the arm f said lever being provided on its face adjacent to thecarrier-drum with suitable friction material to bind against theperiphery of the drum, all as set forth.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing Witnesses, this 6th day of June, A. I).1889.

TALTER S. MCKAY.

Witnesses:

A. D. HARRISON, C. F. BROWN.

